Utility of sAxl and Lp-PLA2 biomarkers in early detection of cardiac allograft vasculopathy in heart transplantation patients

Purpose: Cardiac allograft vasculopathy (CAV) remains one of the major limitations in long-term survival in Heart Transplantation patients (TC). Its diagnosis requires invasive methods and often is done in advanced stages of the disease. The aim of this work is to study the utility of two biomarkers in the early detection of CAV, in particular sAxl (protein involved in vascular remodeling) and Lp-PLA2 (marker of atherosclerosis).
Methods: We studied 96 TC. We obtained peripheral blood samples to analyze sAxl and Lp-PLA2 levels at the time that the coronary angiography was done for the diagnosis of CAV. Cardiac allograft vasculopathy was classified according to the recommendations of the ISHLT.
Results: Study population included 96 patients, aged 48±15 years old, 77% male. In 45 patients the angiographic study did not show CAV (CAV0), in 27 CAV was mild (CAV1), in 5 moderate (CAV2) and in 19 sever (CAV3). We found no significant differences in Lp-PLA2 levels (p=0.8) in patients with or without CAV. In contrast, sAxl levels were significantly higher (64.7 vs 79.3, p=0.03) in patients with CAV (CAV 1,2,3)compared to patients without CAV (CAV0). In the logistic regression analysis sAxl levels >74 were associated with increased risk of CAV (Odds Ratio= 2.367; 95% 1015¿5520; p=0.04).
Conclusion: Monitoring the levels of sAxl could be useful for identifying patients with CAV development. Conversely, Lp-PLA2 levels don¿t seem to be usefull in early detection of CAV. Further studies with larger number of patients may provide more information on the utility of these biomarkers in the early detection of CAV.